Field of the Invention
The present disclosure relates to control of a fixation apparatus included in an image formation apparatus of an electrophotography type.
Description of the Related Art
An image formation apparatus of an electrophotography type has widely been used. An image formation apparatus of an electrophotography type fixes a transferred toner image onto paper with heat. The step of fixing a toner image onto paper is performed by a fixation apparatus.
A fixation apparatus includes a fixation belt, a pressurization roller, a pressing member, and a heating roller. The fixation belt is looped around the heating roller and the pressing member. The fixation belt is in contact with the pressurization roller and rotationally driven by the pressurization roller. The pressing member presses the fixation belt against the pressurization roller. A nip region is thus formed between the fixation belt and the pressurization roller. The heating roller provides through the fixation belt, heat to paper which passes through the nip region. Consequently, the toner image is molten on the paper and fixed to the paper.
When a slide resistance between the fixation belt and the pressing member is high, rotation of the fixation belt is interfered, which results in increase in drive torque of the fixation belt and failure in transportation of paper and misalignment in printing. Lowering in slide resistance between the fixation belt and the pressing member with the use of a lubricant has been known as a method of solving such a problem. Too large an amount of lubricant, however, results in leakage of the lubricant from the fixation belt. In connection with a technique for preventing leakage of a lubricant, for example, Japanese Laid-Open Patent Publication No. 2008-185882 discloses a fixation apparatus capable of recovering a lubricant supplied to a fixation belt.
The fixation apparatus disclosed in Japanese Laid-Open Patent Publication No. 2008-185882 controls an amount of supply and an amount of recovery of a lubricant such that an amount of attachment of the lubricant to a fixation belt is always constant. Even while the fixation apparatus is not operating, the lubricant is attached to the fixation belt. The lubricant is cured as a temperature is lower. As the lubricant is cured, a slide resistance between the fixation belt and the pressing member becomes high. Therefore, in the fixation apparatus disclosed in Japanese Laid-Open Patent Publication No. 2008-185882, torque at the time of start of rotation of the fixation belt increases, which results in failure in transportation of paper or misalignment in printing.